Backquotes/system in Apache f/cgi


I’ve done tons of searching on this so I apologize if this is one of
those common knowledge things. I am relying on Kernel#and Kernel#system to run some command line utilities in my Rails app. This worked great until I moved to Apache (win32). When running FCGI, neither of these methods work (both return nil). When running CGI, system seems to work, but

I have investigated environment and permission issues, but nothing seems
make it work.

Is this a limitation when running in Apache, or am I missing something?
they are supposed to work, is there a good way to debug these methods?